Judging by downloads from the NPM registry, React, Facebook’s popular JavaScript UI library, has seen good fortunes lately as a front-end JavaScript framework while the Backbone framework has slipped. On the back end, Express dominates.

In a study of 28-day download cycles for front-end JavaScript frameworks, NPM, which oversees the popular JavaScript package registry, found that React has been on a steady upward trajectory; it now accounts for about 0.05 percent of the registry’s 13 billion downloads per month as of the fourth quarter of 2017. Web developers as well as desktop and mobile developers are adopting the library and it has spawned an ecosystem of related packages.

On the down side, Backbone, which accounted for almost 0.1 percent of all downloads in 2013, now comprises only about 0.005 percent of downloads (about 750,000 per month). Backbone has declined steeply but is kept afloat by the long shelf life of projects using it, NPM reasoned.

Angular, the Google-developed JavaScript framework, was the second-most-popular framework behind React, when combining the original Angular 1.x with the rewritten Angular 2.x. Version 1.x was at about 0.0125 percent of downloads last month while version 2.x was at about 0.02 percent. Still, Angular as a whole is showing just modest growth.

Another framework, Vue, is growing much faster than both Angular and the Ember framework, although it has thus far ascended to just about 0.01 percent of downloads.

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Fastest-growing front-end JavaScript frameworks

NPM ranked frameworks based on their rate of growth in 2016 and 2017, rather than total download numbers:

Preact

Vue

React

Ember

Express still rules at the back end

NPM’s findings echo, to a degree, the recent “State of JavaScript” report, which found developers interested in React on the front end and Express on the back end. NPM calls Express the “overwhelmingly dominant” solution for back-end services composed in JavaScript.

The next four frameworks behind it are so small it is hard to see them, NPM said. They are Koa, Hapi, Sails, and Next.

Despite commanding the back end, Express accounted for 1.5 percent of total downloads in 2013 but just about 0.1 percent now.